Gifr and Geri

The two fierce and angry hounds of Fjölsviðr who guard the hall of Menglöð. One sleeps by night, the next by day, so that no man may ever enter Menglöð's hall unnoticed.

Svipdagr inquires of Fjölsviðr how one might get past them and the giant replies that the dogs must be fed with the wing-joints of the cock Víðópnir. This animal however, can only be killed with the sword Lævateinn, which is in the possession of Sinmara and she will only award the sword to the one who can bring her the tail feather of Víðópnir, thus creating an unsurmountable paradox.